abnormal psychology

Abnormal psychology is the interpretive and scientific study of abnormal thoughts and behavior in order to understand and correct abnormal patterns of functioning. The definition of what constitutes 'abnormal' has varied across time and across cultures, and varies among individuals within cultures. Today, persistent abnormal functioning is often associated with a mental disorder. In general, abnormal psychology can be described as an area of psychology that studies people who are consistently unable to adapt and function effectively in a variety of conditions. An individual's ability to adapt and function can be affected by a number of variables, including one's genetic makeup, physical condition, learning and reasoning, and socialization.


People have tried to explain and control abnormal behavior for thousands of years. Historically, there have been three main approaches to abnormal behavior: the supernatural, biological, and psychological traditions.

In the supernatural tradition, abnormal behaviors are attributed to agents outside human bodies. According to this model, abnormal behaviors are caused by demons, spirits, or the influences of moon, planets, and stars. During the Dark Ages, many Europeans believed in the power of witches, demons, and spirits. Abnormal behaviors were seen as the work of witches, demons, and spirits. People with psychological disorders were thought to be possessed by evil spirits that had to be exorcised through religious rituals. If exorcism failed, some authorities advocated steps such as confinement, beating, and other types of torture to make the body uninhabitable by witches, demons, and spirits. The belief that witches, demons, and spirits are responsible for the abnormal behavior continued into the 15th century. Swiss alchemist, astrologer, and physician Paracelsus (1493-1541) rejected the idea that abnormal behaviors were caused by witches, demons, and spirits and suggested that people’s mind and behaviors were influenced by the movements of the moon and stars.

This tradition is still alive today. Some people, especially in the developing countries and some followers of religious sects in the developed countries, continue to believe that supernatural powers influence human behaviors. However, this tradition has been largely replaced in Western academia by the biological and psychological traditions.

In the biological tradition, psychological disorders are attributed to biological causes and in the psychological tradition, disorders are attributed to faulty psychological development and to social context.

The Greek physician Hippocrates, who is considered to be the father of Western medicine, played a major role in the biological tradition. Hippocrates and his associates wrote the Hippocratic Corpus between 450 and 350 BC, in which they suggested that abnormal behaviors can be treated like any other disease. Hippocrates viewed the brain as the seat of consciousness, emotion, intelligence, and wisdom and believed that disorders involving these functions would logically be located in the brain.

These ideas of Hippocrates and his associates were later adopted by Galen, the Roman physician. Galen extended these ideas and developed a powerful and influential school of thought with in the biological tradition that extended well into the 19th century.

Core concepts: explaining abnormal behavior

Abnormal psychology consists of three core concepts: cultural and historical relativism, the principle of multiple causality and the connection between mind and body.

Cultural and historical relativism

Throughout time, societies have proposed several explanations of abnormal behavior within human beings. Beginning in some hunter-gatherer societies, animists have believed that people demonstrating abnormal behavior are possessed by malevolent spirits. This idea has been associated with trephination, the practice of cutting a hole into the individual's skull in order to release the malevolent spirits.

A more formalized response to spiritual beliefs about abnormality is the practice of exorcism. Performed by religious authorities, exorcism is thought of as another way to release evil spirits who cause pathological behavior within the person. In some instances, individuals exhibiting unusual thoughts or behaviors have been exiled from society or worse. Perceived witchcraft, for example, has been punished by death. Two Catholic Inquisitors wrote a manual, the Malleus Maleficarum, that became co-opted by many Inquisitors and witch-hunters. It contained an early taxonomy of deviant behavior and proposed guidelines for prosecuting deviant individuals.

The act of placing mentally ill individuals in a separate facility known as an asylum dates to 1547, when King Henry VIII of England established the St. Mary of Bethlehem asylum. Asylums remained popular throughout the Middle Ages and the Renaissance era.

Multiple causality

The number of different theoretical perspectives in the field of psychological abnormality has made it difficult to properly explain psychopathology. The attempt to explain all mental disorders with the same theory leads to reductionism (explaining a disorder or other complex phenomena using only a single idea or perspective). Most mental disorders are composed of several factors, which is why one must take into account several theoretical perspectives when attempting to diagnose or explain a particular behavioral abnormality or mental disorder. Explaining mental disorders with a combination of theoretical perspectives is known as multiple causality.

The diathesis-stress model emphasizes the importance of applying multiple causality to psychopathology by stressing that disorders are caused by both precipitating causes and predisposing causes. A precipitating cause is an immediate trigger that instigates a person's action or behavior. A predisposing cause is an underlying factor that interacts with the immediate factors to result in a disorder. Both causes play a key role in the development of a psychological disorder.

Mind and body

A paradigm is a general viewpoint on the world and is much broader than a theory. Today's field of psychology revolves around two major paradigms for explaining mental disorders, the psychological paradigm and the biological paradigm. The psychological paradigm focuses more on the humanistic, cognitive and behavioral perspectives. The biological paradigm includes the theories that rely more on physical causes such as genetics and neurochemistry.

Recent concepts of abnormality

  • Statistical abnormality - when a certain behaviour/characteristic is relevant to a low percentage of the population. However, this does not necessarily mean that such individuals are suffering from mental illness (for example, statistical abnormalities such as extreme wealth/attractiveness)
  • Psychometric abnormality - when a certain behaviour/characteristic differs from the population's normal dispersion e.g. having an IQ of 35 could be classified as abnormal, as the population average is 100. However, this does not specify a particular mental illness.
  • Deviant behaviour - this is not always a sign of mental illness, as mental illness can occur without deviant behaviour, and such behaviour may occur in the absence of mental illness.
  • Combinations - including distress, dysfunction, distorted psychological processes, inappropriate responses in given situations and causing/risking harm to oneself.p][[l[p]p[


  • Somatogenic - abnormality is seen as a result of biological disorders in the brain (Kraeplin, 1883). However, this approach has led to the development of radical biological treatments e.g. lobotomy.
  • Psychogenic - abnormality is caused by psychological problems. This, too, has led to some esoteric treatments. Mesmer used to put his patients in a darkened room with music playing, then entered wearing a flamboyant outfit and pressed the 'infected' body areas with a stick. It has also led to the development of hypnosis, psychoanalysis (Freud) and catharsis as psychological treatments, as well as humanistic (Carl Rogers, Abraham Maslow).



The standard abnormal psychology and psychiatry reference book in North America is the Diagnostic and Statistical Manual of the American Psychiatric Association. The current version of the book is known as DSM IV-TR. It lists a set of disorders and provides detailed descriptions on what constitutes a disorder such as Major Depressive Disorder or anxiety disorder. It also gives general descriptions of how frequent the disorder occurs in the general population, whether it is more common in males or females and other such facts. The diagnostic process uses five dimensions called 'axes' to ascertain symptoms and overall functioning of the individual. These axes are as follows

  • Axis I - Particular clinical syndromes
  • Axis II - Pervasive disorders (Personality Disorders, Mental Retardation)
  • Axis III - General medical conditions
  • Axis IV - Psychosocial/environmental problems
  • Axis V - Global assessment of functioning (often referred to as GAF)


The major international nosologic system for the classification of mental disorders can be found in the most recent version of the International Classification of Diseases, 10th revision (ICD-10). The ICD-10 has been used by World Health Organization (WHO) Member States since 1994. Chapter five covers some 300 "Mental and behavioural disorders." The ICD-10's chapter five has been influenced by APA's DSM-IV and there is a great deal of concordance between the two. WHO maintains free access to the ICD-10 Online . Below are the main categories of disorders:

  • F00-F09 Organic, including symptomatic, mental disorders
  • F10-F19 Mental and behavioural disorders due to psychoactive substance use
  • F20-F29 Schizophrenia, schizotypal and delusional disorders
  • F30-F39 Mood [affective] disorders
  • F40-F48 Neurotic, stress-related and somatoform disorders
  • F50-F59 Behavioural syndromes associated with physiological disturbances and physical factors
  • F60-F69 Disorders of adult personality and behaviour
  • F70-F79 Mental retardation
  • F80-F89 Disorders of psychological development
  • F90-F98 Behavioural and emotional disorders with onset usually occurring in childhood and adolescence
  • F99 Unspecified mental disorder



  • Investigated through family studies, mainly of monozygotic (identical) and dizygotic (fraternal) twins, often in the context of adoption.
  • These studies allow calculation of a heritability coefficient.

Biological factors

  • Investigates effects of hormones, neurotransmitters and neuron damage in mental illness, for example Alzheimer's Disease (neuronal degeneration), Seasonal Affective Disorder (hormonal imbalance) and depression/anxiety.
  • Different theories focus on structural, biochemical and genetic theories.

Psychological factors

Socio-cultural factors

Systemic factors

  • Family systems
  • Negatively Expressed Emotion playing a part in schizophrenic relapse and anorexia nervosa.

Biopsychosocial factors

  • Holistic causal model
  • Illness dependent on stress 'triggers'.

See also



  • Hansell, James; Lisa Damour (2005). Abnormal Psychology. Von Hoffman Press.
  • Barlow, David H.; Vincent Mark Durand (2004). Abnormal Psychology: An Integrative Approach. Thomson Wadsworth.


  • Hockenbury, Don; Sandra Hockenbury (2003). Psychology. 3rd Edition, Worth Publishing.

External links

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